scholarly journals Red coloration in juvenile spiny-footed lizards, Acanthodactylus erythrurus, reduces adult aggression

2015 ◽  
Vol 102 ◽  
pp. 59-67 ◽  
Author(s):  
Belén Fresnillo ◽  
Josabel Belliure ◽  
José Javier Cuervo
Keyword(s):  
Author(s):  
Е. А. Dolmatov ◽  
Т. А. Khrykina

Development of low-growing varieties is one of the prioritized directions in groups selection. Solution of excessive growth in the selection can be solved in today’s conditions by two means: on a polygenic and on a monogenic level. Up until recently such work was performed by research institutes of horticulture in the U.S.S.R. and Russian Federation only on the polygenic level. The analysis is performed for the data of 17 summer studies on the development of complex donors of monogenic determined dwarfness (gene D), high winter hardiness, group fungal disease resistance (scab, leaf spot and Septoria blight) and bright red coloration of pear fruits (gene C). On the first stage of these studies the issue of the development of population of hybrid dwarf types with high adaptive potential in the conditions of the Central Black Earth region of Russia was solved based on a hybridization of the donors of high winter hardiness and fungal disease resistance with the donors of monogenic determined dwarfness which were the descendants of 4th generation of the NainVert variety. As a result, several complex donors were selected. Its use in long-term pear selection programs would make sorting process possible on earlier stages of the ontogenesis and thanks to that would make it possible to halve the size of hybrid funds. Brief description of the complex donors is given.


2017 ◽  
Vol 4 (3) ◽  
pp. 161009 ◽  
Author(s):  
Pierre-Paul Bitton ◽  
Ulrike K. Harant ◽  
Roland Fritsch ◽  
Connor M. Champ ◽  
Shelby E. Temple ◽  
...  

The light environment in water bodies changes with depth due to the absorption of short and long wavelengths. Below 10 m depth, red wavelengths are almost completely absent rendering any red-reflecting animal dark and achromatic. However, fluorescence may produce red coloration even when red light is not available for reflection. A large number of marine taxa including over 270 fish species are known to produce red fluorescence, yet it is unclear under which natural light environment fluorescence contributes perceptively to their colours. To address this question we: (i) characterized the visual system of Tripterygion delaisi, which possesses fluorescent irides, (ii) separated the colour of the irides into its reflectance and fluorescence components and (iii) combined these data with field measurements of the ambient light environment to calculate depth-dependent perceptual chromatic and achromatic contrasts using visual modelling. We found that triplefins have cones with at least three different spectral sensitivities, including differences between the two members of the double cones, giving them the potential for trichromatic colour vision. We also show that fluorescence contributes increasingly to the radiance of the irides with increasing depth. Our results support the potential functionality of red fluorescence, including communicative roles such as species and sex identity, and non-communicative roles such as camouflage.


1963 ◽  
Vol 41 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Ronald M. Christie ◽  
Helen I. Battle

Larvae of the lamprey, Entosphenus lamottei (Le Sueur), and rainbow trout, Salmo gairdneri Richardson, were exposed to the sodium salt of 3-trifluormethyl-4-nitrophenol (TFM) in concentrations of 0.75 p.p.m., 3.00 p.p.m., and 6.00 p.p.m. Microscopic examination of changes induced in the gills, liver, cloacal region, and musculature were made on 7-micron sections stained with Harris' haematoxylin and Bowie's eosin, and in the gill region with periodic acid Schiff reagent. A comparison of the degree of the effects in the two species was made by planimetry of the vascular, cellular, and edematous areas from enlarged drawings of sections.Upon exposure to lethal concentrations of TFM, the body of the larval lamprey becomes distended at the pharyngeal level and heavy cords of mucus emerge from the external gill clefts. A deep red coloration is evident in the pharyngeal region consequent upon vasodilatation of the arterioles and capillaries of the gill filaments. Trout exhibit a similar vasodilatation of the gills together with increased mucous secretion. Edema in the connective tissue between the respiratory epithelium and the vascular endothelium is induced in both species. After prolonged exposure to TFM, the mucous cells in the lining of the branchial chamber and covering the tips of the gill filaments are actively discharging their secretions or completely spent.Certain effects induced by TFM in the larval lamprey are not evident in the trout. The cloacal region takes on a deep red coloration due to dilatation of the venous sinuses and the liver becomes reddish because of sinusoidal dilatation. Extensive edema of the fibrous connective tissue of the skeletal musculature is characteristically present. A slightly increased secretory activity of mucous-secreting cells may occur in the epidermis.With the techniques employed in this study, there was no evidence in either species of cytological or histological changes in the nervous tissue, cardiac musculature, notochord, alimentary canal (including the haemopoietic typhlosole of the lamprey), or mesonephros.


Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 702
Author(s):  
Ekaterina V. Kaneva ◽  
Roman Yu. Shendrik ◽  
Tatiana A. Radomskaya ◽  
Ludmila F. Suvorova

Fedorite is a rare phyllosilicate, having a crystal structure characterized by SiO4-tetrahedral double layers located between continuous layers formed by edge-sharing (Ca,Na)-octahedra, and containing interlayer K, Na atoms and H2O molecules. A mineralogical-petrographic and detailed crystal-chemical study of fedorite specimens from three districts of the Murun alkaline complex was performed. The sequence of the crystallization of minerals in association with fedorite was established. The studied fedorite samples differ in the content of interlayer potassium and water molecules. A comparative analysis based on polyhedral characteristics and deformation parameters was carried out. For the first time, EPR, optical absorption and emission spectra were obtained for fedorite. The raspberry-red coloration of the mineral specimens could be attributed to the presence of Mn4+ ions.


Author(s):  
Pascal Lorance ◽  
Franz Uiblein ◽  
Daniel Latrouite

Analyses of 13 submersible dives on the continental slope of the Bay of Biscay (north-east Atlantic) showed that: (i) orange roughy formed dense aggregation of more than 4000 individuals per ha close to the bottom of a small underwater canyon. In all other study areas only a few individuals were observed. Orange roughy aggregations are probably associated with areas of high water mass movements and mixing; (ii) most individuals observed within this aggregation or in its peripheral areas were behaviourally inactive and could be approached with the submersible at close distance; (iii) a large number of these orange roughy showed a completely pigmentless white, or weak red coloration, never observed from specimens caught in trawls. Two individuals which were disturbed by the submarine changed from white to the ‘typical’ red coloration.These observations suggest fine tuning of the foraging strategy and life cycle of the species. It is speculated that, as an active predator of a sparse food resource, orange roughy has developed adaptations to exploit areas with specific hydrological conditions which offer high prey encounter rates and shelter during metabolic relaxation phases between foraging trips.


2006 ◽  
Vol 26 (4) ◽  
pp. 507-516 ◽  
Author(s):  
Jong-Sug Park ◽  
Myoung-Gun Choung ◽  
Jung-Bong Kim ◽  
Bum-Soo Hahn ◽  
Jong-Bum Kim ◽  
...  
Keyword(s):  

1988 ◽  
Vol 46 (1) ◽  
pp. 69-72 ◽  
Author(s):  
A. U. Bresolin ◽  
L. Pascuzzi ◽  
R. Melaragno Filho ◽  
Maria H. Fontana ◽  
R. Pécora ◽  
...  

Case report of a 7 1/2-years old girl considered as being normal until the age of 2 years. From then on she progressed with gait disturbance, mental deterioration, dystonic movements, convulsions and dysarthria. She died of bronchopneumonia one year later. CT scan showed hyperdensity at the putamina, with no signs of cerebral atrophy. Pathological examination disclosed an intense red coloration of the putamina and axonal «spheroids» at electron microscopy.


2019 ◽  
Vol 65 (6) ◽  
pp. 633-642
Author(s):  
Belén Fresnillo ◽  
Josabel Belliure ◽  
Diego Gil ◽  
José J Cuervo

AbstractBreeding coloration of females often signals aspects of their reproductive status, suggesting a link between color and sex steroid hormones. In this study, we examined the relationships between 2 sex steroid hormones (progesterone and β-estradiol) and reproductive coloration in female spiny-footed lizards Acanthodactylus erythrurus. We first explored natural variation in female plasma hormone levels and coloration during their reproductive cycle. β-estradiol was negatively related to brightness and positively related to red saturation, whereas progesterone was not significantly related to coloration. After identifying key relationships, plasma hormone concentrations were manipulated by creating 3 experimental female groups (β-estradiol-treated, progesterone-treated, and control), and the effects on coloration were monitored. β-estradiol-treated females, in which there was a rise in both β-estradiol and progesterone levels, lost their red coloration earlier than females in the other 2 experimental groups, whereas progesterone treatment had no significant effect on female coloration. Our results suggest that high levels of either β-estradiol alone or β-estradiol together with progesterone trigger the loss of red coloration in female spiny-footed lizards, and that progesterone alone does not affect coloration. We hypothesize that changes in female breeding color might be regulated by β-estradiol in species in which conspicuous coloration is displayed before ovulation, and by progesterone in species in which this color is displayed during gravidity.


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